Sprinkler accelerator system with pressure change detector

ABSTRACT

In the particular embodiment of the invention disclosed herein, a dry pipe sprinkler system comprises a sprinkler pipe communicating with a plurality of sprinkler heads and normally containing air under pressure. A water pipe normally containing water under pressure is connected to the sprinkler pipe by a dry pipe valve which normally prevents the passage of water. When a sprinkler head is actuated, the dry pipe valve opens and allows the water to flow thereto. For more rapidly opening the dry pipe valve, an accelerator valve responsive to a pressure drop in the sprinkler pipe, directs air to the dry pipe valve so as to increase the pressure on one side thereof. A pressure-responsive control valve is associated with the accelerator valve and normally allows the passage of air to the accelerator valve; however, when the dry pipe valve opens, the control valve closes, thus preventing the passage of water to the accelerator valve.

United States Patent i 13,ss9,445

[[721 lnventor Richard F. Juliane Somers, N.Y. [2| Appl. No 817,695 [22]Filed Apr.21, 1969 [45] Patented June 29, 1971 [73] Assignee TheReliable Automatic Sprinkler Company, Inc. Mount Vernon, N.Y.

[54] SPRINKLER ACCELERATOR SYSTEM WITH PRESSURE CHANGE DETECTOR 7Claims, 2 Drawing Figs.

[52] U.S.Cl 169/17, 169/20 [51] Int. Cl A62c 35/00 [50] Field of Search239/75, 569; 169/16, l7, 19, 20, 22

[56] References Cited K UNITED STATES PATENTS 1,608,074 11/1926 Tyden169/17 169/22 1,689,980 10/1928 Tyden 3,401,751 9/1968 Loftin etal.

Primary ExaminerM. Henson Wood, Jr. Assistant Examiner-Edwin Dv GrantAnomeyBrumbaugh, Graves, Donohue & Raymond ABSTRACT: In the particularembodiment of the invention disclosed herein, a dry pipe sprinklersystem comprises a sprinkler pipe communicating with a plurality ofsprinkler heads and normally containing air under pressure. A water pipenormally containing water under pressure is connected to the sprinklerpipe by a dry pipe valve which normally prevents the passage of water.When a sprinkler head is actuated, the dry pipe valve opens and allowsthe water to flow thereto. For

more rapidly opening the dry pipe valve, an accelerator valve responsiveto a pressure drop in the sprinkler pipe, directs air to the dry pipevalve so as to increase the pressure on one side thereof. Apressure-responsive control valve is associated with the acceleratorvalve and normally allows the passage of air to the accelerator valve;however, when the dry pipe valve opens, the control valve closes, thuspreventing the passage of water to the accelerator valve.

AIR

SUPPLY PATENTEB Juuz lsn 3.589.445

INVBN'IOR. RICHARD F. JULIANO 26 hls ATTORNEYS.

SPRINKLER ACCELERATOR SYSTEM WITH PRESSURE CHANGE DETECTOR BACKGROUND OFTHE INVENTION In order to reduce fire insurance rates and premiums, itis usual to provide buildings with a sprinkler system so that when afire occurs, the system is actuated and provides a water spray over theburning area. In cold climates where the ambient temperature is belowfreezing, it is usual to provide a dry pipe system, that is, one havingair rather than water in the sprinkler pipes. This prevents water fromfreezing in the sprinkler pipes. Dry pipe systems are connected to awater supply by a dry pipe valve and generally utilize an acceleratorvalve which is responsive to a pressure drop in the sprinkler pipe tohasten the opening of the dry pipe valve and, consequently, the flow ofwater to the sprinkler heads. Without an accelerator valve, the dry pipevalve would open after a relatively long delay during which the firecould spread to other areas.

When the dry pipe valve opens, water flows to the accelerator valve andcarries with it rust and other debris from the sprinkler pipe which isdeposited on the internal parts of the accelerator valve. Sinceaccelerator valves are usually delicate pieces of equipment, suchdeposits will cause future malfunctions. It is necessary, therefore,once the system has been opened, to drain the accelerator valve,disassemble and clean it, then reassemble it into its operativeposition. Disassembly of these valves is time-consuming and expensivebecause of their complex nature. I

SUMMARY OF THE INVENTION In accordance with the invention disclosedherein, a control valve mechanism is provided that allows the passage ofair from the sprinkler pipe to the accelerator valve, but upon actuationof the system, will rapidly close to prevent the flow of water anddebris thereto.

More specifically, this invention comprises a pressure responsivecontrol valve that is interposed between a sprinkler pipe and anaccelerator valve and which also communicates with a dry pipe valve.Normally, the control valve is held in an open position by the airpressure in the sprinkler system so that air can flow between thesprinkler pipe and the accelerator valve. When the dry pipe valve opens,the pressure differential across the control valve is reduced, causingthe control valve to close thereby preventing the passage of water anddebris to the accelerator valve. Since the accelerator valve isprotected from debris, it is not necessary to dismantle it after thesystem has been used.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of thepresent invention, reference is made to the following specification andthe accompanying drawings, in which FIG. I is a schematic illustrationof a dry pipe sprinkler system in accordance with this invention, withparts thereof broken away for the sake of clarity; and

FIG. 2 is an enlarged cross-sectional view of the control valve shown inFIG. ll.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The dry pipe sprinklersystem disclosed herein comprises a sprinkler pipe it) normallycontainingair under pressure from a suitable air supply (not shown) andcommunicating with a plurality of sprinkler heads 12 which are normallymaintained in a closed position. The sprinkler heads 12 may be of anysuitable type and generally include a valve means with a fusiole link13. When the temperature increases above a predetermined point, a link13 will melt and open its associated valve i that water may be sprayedover the area under the sprinkler lead I21.

A source of water under pressure (not shown) communicates with thesprinkler pipe through a suitable water pipe 14 and a dry pipe valve 16which normally prevents the passage of water. Any suitable dry pipevalve may be utilized and for the purpose of illustration only one suchvalve is disclosed herein and includes a rectangular housing 18 formedwith an upstanding wall member 20 on its bottom face. The water pipe 14and upstanding wall 20 project the same height above the bottom of thehousing and are concentric so as to provide an annular chamber 22therebetween. Pivotally mounted in the valve 16 is a clapper member 24having a sealing membrane 25 on its under face that seats across thechamber 22 and pipe 14. Due to the air pressure in the system, theclapper member 24 is retained in its closed position. Actually, the airpressure is lower than the water pressure, but the area over which theair acts (the upper face of the clapper) is so much greater than thearea over which the water acts (the area of the pipe) that the downwardforce on the clapper is greater than the upward force. Thus, the clapperis overbalanced in the closed position. Inside the valve housing 18, asmall amount of water is provided so as to prime the system and the airpressurizes the water downwardly along the upper face of the clapper. Itis to be understood, of course, that priming water need not be used.

A conduit 26 extends from the upper face of the housing 18 andcommunicates with the sprinkler pipe 10 and the air therein. Of course,conduit 26 could communicate directly with the sprinkler pipe 10,- butin the interest of economy, communicates with the housing 18. At itsother end, the conduit 26 is connected to a control valve 28, thepurpose of which will be fully explained hereinafter. Another conduit 30extends from the control valve 28 and communicates with an acceleratorvalve 32 which in turn communicates with the intermediate chamber 22 ofthe dry pipe valve by a conduit 34. It is to be understood that theaccelerator 32 is responsive to a pressure drop in the sprinkler pipe 10caused by the opening of a sprinkler head 12 and causes an air flowthrough conduit 34 to the intermediate chamber 22 of the dry pipe valve16 where it exerts a force on the underside of the clapper 24.

Any suitable accelerator valve may be used, one such device beingdescribed in US Pat. No. 1,913,245 issued on June 6, 1933 to Rowley. Inthat patent there is disclosed a device capable of operating as eitheran exhauster or an acceleratorand for the purpose of this invention, thelatter function is intended.

A restricted vent member 36 and a suitable check valve 38 are providedat the outlet side of the accelerator valve 32 for a purpose to be fullyexplained hereinafter. Extending from an upper portion of the valve 28is a conduit 40 connected to the conduit 34 at the downstream side ofthe vent 36 and check valve 38 so as to communicate with chamber 22 ofthe dry pipe valve 16.

In accordance with the invention, the control valve 28 is operative toallow the passage of air between the sprinkler pipe 10 and theaccelerator valve 32, but to prevent the passage of water and debristhereto. In the embodiment of the invention disclosed herein, thecontrol valve is pressure responsive and comprises an upper housing 42and a lower housing 44 secured together by suitable fasteners 48.Carried in the lower housing 44 are the conduits 26 and 30 and a valveseat 50 having a central passage 51 across which the conduitscommunicate. Clamped between the housings 42 and 44 is a flexiblediaphragm 46, the central portion of which is sandwiched betweenstiffener plates 52 and 54. The lower stiffener plate 54 has aprojecting stud 55 that is received in an opening in the diaphragm 46and upper stiffener plate 52. A nut member 56 is threaded on the stud 55to secure the plates together. Carried on the lower face of thestiffener plate 54 is a suitable seal member 58 that cooperates with thetop of the valve seat 50 to prevent the passage of water. Biasing thediaphragm 46, plates 52 and 54, and the seal member 58 downwardlyagainst the seat 50 is a spring member 60 carried in the upper housing.Of course, other biasing arrangements could be provided, but a spring ispreferred because of its economy and simplicity. The conduit 40 isconnected to the upper housing portion 42 and communicates with acontrol chamber 62 formed between the diaphragm 46 and the upperhousing.

The sprinkler system operates in a manner described hereafter. Theclapper member 24 is pivoted to its closed position as shown in FIG. Iand a small amount of priming water is introduced into the dry pipevalve 16. Air is then introduced into the sprinkler pipe at a pressuresufficient to retain the clapper 24 in the closed position and, also, tobias the plate members 52 and 54 against the spring 60 to an openposition. Thereafter, water is introduced into the water pipe 14 at apressure, as pointed out previously, much higher than the pressure ofthe air. The system is now operative.

When a fire occurs, one or more of the sprinklers 12 will open causing apressure drop in the pipe 10, housing 18 and pipes 26 and 30. Thispressure drop will decrease the force on the upper face of the clapper24 and also actuate the accelerator 32 causing air to flow through theconduit 34 to the intermediate chamber 22 of the dry pipe valve 16.During this time, the plate members 52 and 54 are retained in an openposition since the pressure drop is not sufficient to allow the spring60 to bias them to a closed position. As air from the accelerator 32 isfed into the intermediate chamber 22 and as the pressure drops insidethe housing 18, a point will be reached, rather rapidly, wherein theforce on the bottom of the clapper 24 exceeds that on the top thereof.At this time, the clapper will be pivoted to its dotted line positionallowing water from the pipe 14 to flow through the pipe 10 to theappropriate sprinkler head 12. Of course, water will also flow throughpipe 26 toward the accelerator 32. Simultaneous with the opening of theclapper 24, the pressure differential between the conduits 26 and 40 isequalized. Because of the pressure drop across the valve seat 50resulting from the flow of air, the pressure in the conduit 30 is lowerthan the pressure in conduits 26 and 40 and the spring 60 causes theplate members 52 and 54 to move downwardly across the seat 50. Since allof the above happens simultaneous with the opening of the clapper 24, nowater can pass through the control valve 28, thus the accelerator 32 isprotected from water and debris. Check valve 38 prevents the backup ofwater or air to the accelerator and any air remaining in the acceleratorand the conduit 30, is bled out through the vent 36.

When the fire is extinguished, the system may be reset as describedpreviously and there is no need to dismantle and clean the acceleratorvalve 32.

While in the foregoing there has been disclosed an illustrativeembodiment of this invention, various modifications will occur to thoseskilled in the art to which this invention pertains. Accordingly, it isnot desired to limit the invention to the exact features disclosed, butto encompass all modifications that fall within the scope of theappended claims.

Iclaim:

1. A dry pipe sprinkler system comprising dry pipe valve meanscommunicating with a source of water under pressure and a sprinkler pipecontaining air under pressure, the dry pipe valve means being normallyretained in a closed position by the air pressure in the sprinkler pipe,accelerator means connected to the sprinkler pipe and responsive to areduction in air pressure therein to supply air to the dry pipe valvemeans to accelerate the opening thereof, and pressure-responsive controlvalve means for sensing accelerator means actuation and an air-pressuredrop across said control valve means as the dry pipe valve means opens,to shut off communication between the accelerator means and thesprinkler pipe.

2. A sprinkler system as defined in claim 1 wherein the control valvemeans is connected to the dry pipe valve means so that the pressureincrease in said sprinkler pipe caused by the opening of the dry pipevalve means will be transmitted to the control valve means to cause theclosing thereof.

3. A sprinkler system as defined in claim 1 wherein the control valvemeans is interposed in the connection between the sprinkler pipe and theaccelerator means.

4. A sprinkler system as defined in claim 3 wherein the control valvemeans is also connected to the dry pipe valve means.

5. A sprinkler system as defined in claim 4 wherein the control valvecomprises a housing divided into first and second chambers by a flexiblediaphragm, the first chamber allowing communication between thesprinkler pipe and the accelera' tor means and the second chambercommunicating with a portion of the dry pipe valve means connected withthe accelerator means output.

6. A sprinkler system as defined in claim 1 wherein the acceleratormeans is connected to the dry pipe valve means and wherein theconnection includes a restricted vent and a check valve.

7. A dry pipe sprinkler system comprising a sprinkler pipe includingsprinkler heads and normally containing air under pressure and a waterpipe containing water under pressure, a dry pipe valve means interposedbetween the sprinkler pipe and the water pipe for controlling the flowof water from the water pipe to the sprinkler pipe, an accelerator valvemeans communicating with the sprinkler pipe and an intermediate portionof the dry pipe valve means for more rapidly opening the dry pipe valvemeans, a control valve means communicating with the sprinkler pipe andthe accelerator valve means and having an opening position allowing thepassage of air between the sprinkler pipe and the accelerator valvemeans, the control valve means also communicating with the intermediateportion of the dry pipe valve means and being responsive to twoconditions for moving to a closed position preventing the passage ofwater to the accelerator valve means, said to conditions being apressure increase at the dry pipe valve intermediate portion and airmovement past the control valve means toward the accelerator.

1. A dry pipe sprinkler system comprising dry pipe valve meanscommunicating with a source of water under pressure and a sprinkler pipecontaining air under pressure, the dry pipe valve means being normallyretained in a closed position by the air pressure in the sprinkler pipe,accelerator means connected to the sprinkler pipe and responsive to areduction in air pressure therein to supply air to the dry pipe valvemeans to accelerate the opening thereof, and pressure-responsive controlvalve means for sensing accelerator means actuation and an air-pressuredrop across said control valve means as the dry pipe valve means opens,to shut off communication between the accelerator means and thesprinkler pipe.
 2. A sprinkler system as defined in claim 1 wherein thecontrol valve means is connected to the dry pipe valve means so that thepressure increase in said sprinkler pipe caused by the opening of thedry pipe valve means will be transmitted to the control valve means tocause the closing thereof.
 3. A sprinkler system as defined in claim 1wherein the control valve means is interposed in the connection betweenthe sprinkler pipe and the accelerator means.
 4. A sprinkler system asdefined in claim 3 wherein the control valve means is also connected tothe dry pipe valve means.
 5. A sprinkler system as defined in claim 4wherein the control valve comprises a housing divided into first andsecond chambers by a flexible diaphragm, the first chamber allowingcommunication between the sprinkler pipe and the accelerator means andthe second chamber communicating with a portion of the dry pipe valvemeans connected with the accelerator means output.
 6. A sprinkler systemas defined in claim 1 wherein the accelerator means is connected to thedry pipe valve means and wherein the connection includes a restrictedvent and a check valve.
 7. A dry pipe sprinkler system comprising asprinkler pipe including sprinkler heads and normally containing airunder pressure and a water pipe containing water under pressure, a drypipe valve means interposed between the sprinkler pipe and the waterpipe for controlling the flow of water from the water pipe to thesprinkler pipe, an accelerator valve means communicating with thesprinkler pipe and an intermediate portion of the dry pipe valve meansfor more rapidly opening the dry pipe valve means, a control valve meanscommunicating with the sprinkler pipe and the accelerator valve meansand having an opening position allowing the passage of air between thesprinkler pipe and the accelerator valve means, the control valve meansalso communicating with the intermediate portion of the dry pipe valvemeans and being responsive to two conditions for moving to a closedposition preventing the passage of water to the accelerator valve means,said to conditions being a pressure increase at the dry pipe valveintermediate portion and air movement past the control valve meanstoward the accelerator.